The Committers of a Project or component decide which changes may
be committed to the master code base of a Project or component respectively. The
PMC defines the decision process, but that
process must include the ability for Committers to veto the change. The decision process employed may change with the
phase of development. Common decision processes include:

Retroactive - changes are proactively made by Committers but can be
vetoed by a single Committer.

Proactive - for efficiency, some code changes from some
contributors (e.g. feature additions, bug fixes) may be approved in advance, or approved in principle based on an outline of the
work, in which case they may be committed first and changed as needed, with conflicts resolved by majority vote of
the Committers of the Project or component, as applicable.

Three Positive - No code is committed without a vote; three +1 ('yes'
votes) with no -1 ('no' votes or vetoes) are needed to approve a code change.

Vetoes must be followed by an explanation for the veto within 24 hours
or the veto becomes invalid. All votes are conducted via the developer mailing list associated with the Project or
component. Special rules may be established by the PMC for Projects or components with fewer than three Committers.